Not long after they posed for this picture, one of those friends, Mahamd Hassan, was dead, shot in the face by Rapovski, a victim of his "extremely stupid behaviour".

"Guns, drugs and stupidity do not mix, never have, never will," Supreme Court Justice Michael Croucher said on Thursday, before sentencing Rapovski to eight years' jail.

Rapovski, 20, was drug-affected when he and his friends posed with the gun as if they were "would-be gangsters" in photos at the Parkside Inn Motel in Kingsbury in Melbourne's north east on March 5, the judge said.

Mr Hassan, 22, had told Rapovski when he arrived at the motel room to unload the gun in case he shot someone, and another friend helped to remove two cartridges from the weapon.

Rapovski later reloaded the gun with a cartridge, reassuring his friends that the safety switch was on.

Rapovski asked Mr Hassan to take a photo of him with the gun. Mr Hassan held up his mobile phone camera as Rapovski put the gun to his head.

He shot Mr Hassan in the face, leaving a large wound to his mouth and neck area, and screamed "I shot Mo, I shot Mo", before fleeing the room. Mr Hassan died instantly, the court heard.

The man later got rid of the gun, which has never been found.

Justice Croucher said he was not satisfied beyond reasonable doubt as to whether Rapovski had pulled the trigger thinking it wouldn't discharge, or without knowing it was loaded, or believing the safety switch was working, or whether he had accidentally pulled the trigger.

He sentenced Rapovski to a five-year non-parole period for manslaughter, on the basis that he had pulled the trigger accidentally without intending to fire it.

The judge said Rapovski had committed an "unlawful and dangerous act" resulting from "extremely stupid behaviour".

The circumstances of the case also equally met the criteria for criminal negligence.

He did not have a license for the gun, did not know how to use it properly, and was "nonchalant" and "arrogant" about his friends' concerns about the dangers of the gun.

Rapovski must have known he should not have handled the gun as he had been awake for days at the time under the influence of drugs, the judge said.

A reasonable person would have known this risked seriously injuring Hassan, he said.

The day after he killed Hassan, Rapovski tried to fly to Macedonia, telling a travel agent he needed to leave urgently because his grandmother was sick, but was detained by Border Force staff at the airport and later arrested.

Justice Croucher said it was "disgraceful" for him to flee the scene.

While there was nothing he could have done to help his friend at that stage, he had a "moral duty" to stay and report the death to authorities.

Later, he had time to calm down after his "earlier cowardice" but instead chose to continue to avoid responsibility.

The judge accepted that Rapovski was genuinely sorry for his crime and said he had good prospects for rehabilitation.

A psychologist had told the court he showed symptoms of trauma and his fiancee said he was constantly living with guilt and was plagued with the images from that night.